1. Field of the Invention
This invention generally relates to collapsible wind propelled and other water crafts.
2. Background Information
The superior nautical qualities of catamaran type water craft are well known. Their high beam-to-length ratio and their shallow draft provide desirable stability and resistance to capsizing, and they are faster than single hulled water craft. One drawback to catamarans is the awkward bulk of the double hull design which makes handling, transportation and storage difficult and inconvenient. The storage of conventional catamarans is expensive and inconvenient because it occupies a great deal more space than an equivalent sized single hull boat, which also makes it impossible to dock in narrow marina slips.
To overcome these problems, there have been attempts in the past to design a catamaran which collapses into a package that can be more readily transported or which can be contained in a marina slip/dock. Wassell U.S. Pat. No. 3,839,979 discloses a pair of hinged brace spars located on top of juxtaposed pontoons and operated by a control spar which juts out rearwardly and awkwardly when the catamaran is deployed. Skandaliaris et al U.S. Pat. No. 4,909,169 discloses a collapsible multiple hull boat using a tandem series of what is described as xe2x80x9cscissor-like toggle mechanismsxe2x80x9d between and connected by hinges to the opposing upright surfaces of juxtaposed hulls. Russian patent 524,728, discloses a collapsible catamaran having hulls joined by tandem pairs of pivotally movable powered arms. Hall U.S. Pat. No. 6,000,355 discloses a stabilized water craft employing two parallel, laterally spaced pontoons disposed on either side of the water craft for stabilizing the water craft. The pontoons are secured to the sides of the water craft with scissors-like extensor arms, one pair on each side of the water craft, which when collapsed, urge the pontoons toward the water craft. Each pair of extensor arms cross in scissors-like fashion and are connected at a central pivot joint. Nimmo U.S. Pat. No. 3,179,960 discloses a knock-down pontoon boat having laterally spaced, parallel pontoons that may be collapsed toward one another so as to decrease the width of the boat for hauling on vehicle tops. Scissors-like spacer members located on top of the Nimmo pontoons rotate about their pivot to lie substantially flat. Green U.S. Pat. No. 5,373,799, discloses a collapsible sailing rescue water craft provided with port and starboard pontoons that may be urged toward a center portion of the water craft via scissors-like struts that slide along rails on opposite sides of a central hull. French patent 2,610,890 discloses a catamaran having two opposing, parallel, laterally spaced hulls which can be pivotally collapsed toward a central bridge via tandem pivoting frame links connected on top of the hulls and which are not scissors-like structures. Susman U.S. Pat. No. 4,172,426, discloses a trimaran having outriggers or hulls that are pivotally collapsible with tandem swinging arms connected to top of the outriggers to reduce the width of the water craft. Knudsen et al U.S. Pat. No. 55,675 discloses tandem, scissors-like flat, horizontal bars mounted onto the top surface of pontoons to provide a portable life boat. Robinson U.S. Pat. No. 3,139,058 discloses a collapsible motor boat having collapsible hulls via pivotable frame members.
The foregoing designs have been either excessively complicated and expensive to manufacture and maintain, or flimsy and unseaworthy, and frequently require complicated and time consuming procedures for collapse. Moreover, they do not allow the mast of a sail to remain upright while collapsing the water craft while still floating on water. The need exists for a collapsible catamaran type water craft that has a traditional catamaran look and stability but which can be collapsed into a compact package while floating on the water, with the mast in place in its upright position for docking; the mast can be lowered when placed on a trailer.
The present invention provides such a catamaran type water craft. The two laterally spaced, parallel hulls of a catamaran are collapsed toward one another, while being maintained in an upright floating position, via two tandem pairs of scissors-like aft and fore folding mechanisms disposed between and pivotally connecting to the opposing upright surfaces of adjacent, juxtaposed hulls. The folding mechanisms comprise two pairs of overlapped cross-linked beams joined about central pivot joints. A center beam is disposed between and pivotally connects the aft and fore folding mechanisms. A pair of cross-linked overlapped forward bow beams can also be provided arranged so as to rise at an increasing angle to the water craft as the water craft collapses. When the boat is collapsed, the cross-linked beams fold like closing scissors to bring the opposing hulls laterally together, and the bow beams are drawn together, allowing the catamaran to fold to a width that can be transported by a truck or placed in a marina docking slip with the mast in its upright position. A mast is located in the pivot structure of the forward pair of crossed overlapped links, and retained in an upright position by the interaction of tensioning lines connecting the mast to the cross-linked fore beams and shrouds connecting the mast to opposite sides of the boat. Portions of the scissors-like structure forward of the pivot can be omitted if overlap of the pivot areas is retained.
The invention thus has several important structural features, all of which work together to provide a catamaran that can be collapsed while still floating so that it may be easily maneuvered into a standard marina boat slip. The mast can be retained in an upright disposition until it is desired to lower it to place the catamaran on a trailer.
The prior art has not appreciated the combination of structural features presented by the present invention. None of the prior art of which applicant is aware discloses the disposition of the mast of a sail on a pivot joint, and the prior art is deficient in other respects. Wassell U.S. Pat. No. 3,839,979 does not disclose the tandem disposition of overlapped scissors-like struts between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. The toggle mechanisms of Skandaliaris et al U.S. Pat. No. 4,909,169 do not permit overlap of the pivot areas. Russian patent 524,728 does not disclose overlapped scissors-like struts. Hall U.S. Pat. No. 6,000,355 does not disclose the tandem disposition of the pairs of extensor arms between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. Nimmo U.S. Pat. No. 3,179,960 does not disclose the tandem disposition of pairs of the spacer members between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. Green U.S. Pat. No. 5,373,799 does not disclose the tandem disposition of the scissors-like struts between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. French patent 2,610,890 does not disclose overlapped scissors-like struts between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. Susman U.S. Pat. No. 4,172,426 does not disclose the tandem disposition of pairs of overlapped scissors-like arms between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. Knudsen et al U.S. Pat. No. 55,675 does not disclose the arms disposed between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls. Robinson U.S. Pat. No. 3,139,058 does not disclose scissors-like arms between and pivotally connecting to the opposing upright surfaces of juxtaposed hulls
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the drawings of the invention that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, will be better understood from the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.